This invention pertains generally to equipment for executing fabrication protocols directed at producing ultraminiature devices such as microelectronic devices, integrated circuits, display matrices, and the like on a substrate such as a semiconductor wafer. More specifically, the invention pertains to holding and moving mechanisms that provide precision movement and positioning of the reticle and/or substrate during execution of a process such as microlithography is performed on the substrate. The stages according to the invention are especially suitable for operation in a vacuum environment in which microlithography is performed using a charged particle beam.
In view of the extremely high accuracy and precision required in contemporary fabrication processes performed on semiconductor wafers and other substrates, various configurations of substrate stages (generally termed xe2x80x9cwafer stagesxe2x80x9d herein) have been developed for use in providing high-precision movement and positioning of the substrate. Similar developments also have occurred with respect to reticle stages. The respective configurations often reflect the particular fabrication process and process conditions in which the stages are used. The various configurations also reflect the urgent need to minimize vibration and friction in the stage as much as possible.
An example conventional wafer stage assembly is disclosed in Japan Kxc3x4kai Patent Document No. Sho 62-182692. This wafer-stage assembly includes dual guide shafts and is suspended on box-shaped air bearings (gas bearings). An oblique view of the stage assembly 140 is shown in FIG. 30. The stage assembly 140 includes a base 141 and a pair of box-shaped base guides 142 mounted on the base 141. Permanent magnetic plates (not detailed) are affixed to the inside surfaces of the base guides 142, thereby forming respective motor yokes 142a. Engaged at the upper portion of each of the two base guides 142 is a respective box-shaped coil bobbin 143. The motor yokes 142a and coil bobbins 143 collectively comprise a first linear motor providing movement of a wafer stage 146 in the X direction. A box-shaped movable guide member 144 extends between the coil bobbins 143, thereby connecting the coil bobbins together. A permanent magnetic plate (not detailed) is affixed to the inside surface of the movable guide member 144, thereby forming a motor yoke 144a. Engaged at the upper portion of the movable guide member 144 is a box-shaped coil bobbin 145. The motor yoke 144a and coil bobbin 145 collectively comprise as second linear motor providing movement of the wafer stage 146 in the Y direction. The wafer stage 146 is mounted to the coil bobbin 145.
To form air bearings, air-discharge holes (not shown in FIG. 30) are defined on respective surfaces inside the coil bobbins 143, 145 at locations opposite the respective motor yokes 142a, 144a. The air bearings are constituted by discharging air from the air-discharge holes into gaps between the coil bobbins 143, 145 and the respective motor yokes 142a, 144a. 
The wafer-stage assembly shown in FIG. 30 has a configuration in which one movable body (i.e., the guide member 144 and coil bobbin 145) is situated over the upper portion of the other movable body (i.e., the base guide 142 and coil bobbin 143). In other words, the movable body constituted by the guide member 144 and coil bobbin 145 is stacked relative to the movable body constituted by the base guide 142 and coil bobbin. With this stacked configuration, the lower movable body must be large to support the upper movable body adequately. Also, the configuration of FIG. 30 cannot be used in a vacuum because this stage assembly provides no way in which to recover air discharged from the air bearings.
Another conventional wafer stage assembly, disclosed in International application no. WO 99/66221, has a single-shaft configuration that can be used in a vacuum environment. The stage assembly includes a movable body including air-bearing pads. An elevational section of this stage assembly 150 is shown in FIG. 31 and an oblique view of certain details of an air bearing in this stage assembly 150 is provided in FIG. 32.
The stage assembly 150 is mounted on a surface S of a base 151. Two C-shaped guide members 152 are mounted to the bench 151 via respective support members 155. The respective openings in the guide members 152 face each other so as to guide movement of a movable member 153. The fit of the movable member 153 in the openings of the guide members 152 allows a small gap between the movable member 153 and the inside surfaces of the openings. The gap provides an air bearing between the movable member 153 and the guide members 152. A wafer stage 161 is mounted to an upper surface of the movable member 153. A wafer 163 or other suitable substrate is mounted to the wafer stage 161.
The lower surface of the movable member 153 is mounted to a moving member (armature) 156 having a downwardly protruding () tongue. The tongue fits into an upwardly opening groove defined in a stator 157 having a -shaped section. The stator 157 extends along a center line (extending in the Y direction) of the stage assembly 150 on the installation surface S. The tongue of the armature 156 fits into the groove in the stator 157 with a small gap therebetween, thereby forming a linear motor. Thus, the member 153 is movable in the Y direction (perpendicular to the plane of the page).
The configuration of an air bearing is described further, with reference to FIG. 32. As noted above, air bearings are defined between the opposing faces of a guide member 152 and the movable member 153 that slides between opposing faces of the guide member 152. Each guide member 152 comprises an upper portion 152a, a side portion 152b, and a lower portion 152c. In FIG. 32, an upper portion 152a has been pivoted upward (note arc-shaped arrow A1) from the position indicated by broken lines to reveal detail, and the side portion 152b has been pivoted downward (note arc-shaped arrow A2) from the position indicated by broken lines to reveal detail.
Defined on the depicted upper surface and end surface of the movable member 153 are respective pairs of air pads 153a. Each air pad 153a comprises a porous material transmissive to a gas. The gas is supplied from a gas source 158 to the air pads 153a via a conduit 153b. Each pair of air pads 153a is surrounded by a respective xe2x80x9cguard ringxe2x80x9d 153c. A respective gas-exhaust port 154a is defined in the upper portion 152a and the side portion 152b opposite the respective guard ring 153c on the movable member 153. A rotary exhaust pump 159 is connected to the gas-exhaust port 154a via an exhaust conduit 154b. Thus, gas discharged from the air pads 153a is exhausted by the exhaust pump 159.
The movable member 153 moves in the Y direction in FIGS. 31 and 32. In FIG. 32, selected end positions of the movement range of the guard ring 153c are shown by the broken lines on the inside surface of the side portion 152b. As can be understood from this figure, within the range of movement of a guard ring 153c, the guard ring 153c remains at all times in communication with the respective gas-exhaust port 154a. Thus, gas discharged from the air pads 153a is collected by the respective gas-exhaust ports 154a and exhausted with almost no leakage to the chamber or other vacuum environment in which the stage assembly is located.
The stage assembly disclosed in WO 99/66221 can be used in a vacuum. However, this stage assembly has several disadvantages. First, it is based on a single movable member 153 that moves only along one axis (X or Y). If two-dimensional movement of the wafer stage 161 is required or desired, then two movable members are required that must be stacked relative to each other, resulting in a large and bulky structure. Second, two respective air pads 153a are provided on each upper surface and each side surface of the movable member 153. If the stage assembly is configured to have two movable members, then the number of air pads is correspondingly larger, with a correspondingly larger leakage of gas into the vacuum environment of the stage assembly. Third, because the conduit 153b for supplying gas to the air pads 153a is connected to the movable member 153, the tensile strength of the conduit 153b can exert an adverse influence on the controllability of the movable member 153.
Yet another conventional stage assembly is disclosed in U.S. Pat. No. 5,760,564. This stage assembly provides pressurization, in the Z direction, to the wafer stage using air bearings and vacuum pads. FIG. 33 is an oblique view of this stage assembly 170 and FIG. 34 is a plan view.
The stage assembly 170 comprises a base 171. Extending along opposing edges of the upper surface of the base 171 are respective first guide bars 173a, 173b extending in the Y direction. Extending along the other opposing edges of the upper surface of the base 171 are respective second guide bars 174a, 174b extending in the X direction. The first guide bars 173a, 173b include respective stators (arrays of permanent magnets) 176a, 176b arranged along the respective under-surfaces of the first guide bars 173a, 173b. The second guide bars 174a, 174b include respective stators (arrays of permanent magnets) 177a, 177b arranged along the respective under-surfaces of the guide bars 174a, 174b. 
A Y-movable member 179 extends between the first guide bars 173a, 173b and moves in the Y direction. Linear-motor armature coils (not shown) are provided at each end of the Y-movable member 179. These armature coils, along with the stators 176a, 176b, constitute a first linear motor.
Similarly, an X-movable member 178 extends between the second guide bars 174a, 174b and moves in the X direction. Linear-motor armature coils (not shown) are provided at each end of the X-movable member 178. These armature coils, along with the stators 177a, 177b, comprise a second linear motor.
A wafer stage 181 is mounted on the movable members 178, 179 so as to be slidable in the X direction relative to the Y-movable member 179 and slidable in the Y direction relative to the X-movable member 178. The wafer stage 181 includes an electrostatic chuck 180 or the like to which a wafer W is mounted.
As shown in FIG. 34, air bearings 183a, 183b, 183c, 183d are provided below the X-movable member 178. The air bearings 183a-183d prevent the X-movable member 178 from contacting the surface of the base 171, so as to reduce friction. Similarly, air bearings 184a, 184b, 184c, 184d are provided below the Y-movable member 179 and provide a similar function with respect to the Y-movable member 179. An additional air bearing 184e is provided at the center of the base 171 to provide a bearing for the mechanical load (stage 181, etc.) on the center of the Y-movable member 179. In addition, three air bearings 185a, 185b, 185c are provided below the stage 181. These air bearings 185a-185c support the load of the stage 181 directly on the base 171.
Thus, with the stage assembly 170, Z-direction suspension of the wafer stage 181 relative to the base 171 is provided by air bearings. This scheme simplifies the manner in which the air bearings are pressurized and allows the overall mass of the assembly (including the wafer stage 181) to be reduced compared to the configuration disclosed in Japan Kxc3x4kai Patent Document No. Sho 62-182692. Unfortunately, however, in a vacuum the air bearings of this stage assembly cannot be pressurized properly. Whereas Z-direction suspension could be achieved using magnetic levitation, such a scheme is difficult to use in a charged-particle-beam microlithography apparatus, which is exquisitely sensitive to magnetic-field fluctuations.
In addressing the shortcomings of the prior art as summarized above, an object of the invention is, inter alia, to provide improved stage apparatus that can be used in a vacuum environment and that exhibits better controllability than conventional stage apparatus.
To such end, and according to a first aspect of the invention, stage apparatus are provided for moving and positioning a stage within a guide plane. An embodiment of such a stage apparatus comprises a stage and a support structure comprising first and second linear-motor stators. The stage is connected to an arm member having a first end extending from the stage in a first direction and a second end extending from the stage in a second direction opposite the first direction in a plane parallel to the guide plane. First and second sets of linear-motor xe2x80x9cmoversxe2x80x9d (armatures) are arranged on the first and second ends, respectively. The movers are configured to interact with the first and second linear-motor stators, respectively, so as to achieve motion, relative to the support structure, of the arm member and stage in the guide plane.
The stage preferably is situated at the center of the arm member. By arranging the movers symmetrically relative to the stage, movements of the stage are made very smooth. Also, by situating the movers at respective ends of the arm member separately from the stage, magnetic-field fluctuations accompanying movements of the movers relative to the stators are isolated more effectively from the stage.
This stage apparatus can include a guide bar connected to the arm member. The guide bar has a first end extending from the stage in the first direction and a second end extending from the stage in the second direction. Each end of the guide bar comprises a respective bearing by which the guide bar slides relative to a respective surface on the support structure without contacting the support structure. The bearings desirably are air bearings or, more generally, gas bearings that provide a near-frictionless motion of the guide bar (and hence the arm member and stage) relative to the respective surfaces on the support structure.
The arm member desirably defines a conduit, internal with respect to the arm member, that conducts a coolant fluid to and from the mover coils. The arm member can include any of various other conduits as required, for example a conduit for conducting air to and from the air bearings. These internal conduit(s) eliminate the need for external conduits that otherwise interfere with free motion of the stage.
According to another embodiment, a stage apparatus according to the invention comprises a support structure, a stage, and a guide bar. The guide bar is attached to the stage and defines at least three end portions extending in respective directions from the stage in a plane parallel to the guide plane. Each end portion comprises a respective plane bearing configured to support the respective end portion relative to the support structure without the respective plane bearing contacting the support structure. This combination of a guide bar and plane bearings more effectively maintains the stage as required (e.g., horizontally) within the guide plane and reduces drive friction.
This apparatus configuration can further include an arm, having first and second ends, connected in a parallel manner to the guide bar. Each of the first and second ends of the arm includes at least one respective linear-motor mover. The support structure further comprises a respective linear-motor stator for the respective mover(s) on each of the first and second ends of the arm. Hence, each respective linear-motor mover interacts with the respective linear-motor stator so as to achieve motion of the arm, guide bar, and stage, relative to the support structure, in the guide plane.
Each plane bearing can be configured as a gas bearing comprising at least one gas-bearing pad. In this configuration, the guide bar desirably defines internal conduits providing gas supply to and gas recovery and exhaust from the gas bearings.
According to yet another embodiment, a stage apparatus comprises a stage and a plurality of arm members connected to and extending from the stage. Each arm member has respective first and second end portions each having attached thereto a respective linear-motor mover. The apparatus also includes a plurality of guide bars extending from the stage. Each guide bar has at least one respective end portion including a non-contacting bearing. The apparatus also includes a support structure that comprises (1) a respective linear-motor stator associated with each of the linear-motor movers, and (2) a respective guide plate associated with each linear-motor stator (wherein the bearings are configured to slide along respective guide plates). The stators and respective guide plates are arranged in a stacked configuration relative to each other in a direction perpendicular to the guide plane.
According to yet another embodiment, a stage apparatus according to the invention comprises a support structure, a main stage, and a substage. The main stage is configured to hold a process object and to move, with the process object, relative to the support structure within a guide plane. The substage is situated relative to the main stage and the support structure. The substage is configured to mediate flow of a fluid to and from the main stage while the substage is being moved and positioned relative to the main stage. The substage also reduces warping of the main stage.
The main stage and substage desirably interrelate with each other via non-contacting plane bearings situated at respective interrelation portions of the main stage and substage at which the main stage and substage, respectively, interrelate with each other. The flow of the fluid to and from the main stage desirably occurs at the respective interrelation portions. The plane bearings can be respective air bearings each comprising a respective air pad.
This embodiment also can include a linear motor situated and configured to drive the main stage in the guide plane relative to the support structure. The linear motor desirably comprises a respective linear-motor stator at each of the interrelation portions. In such a configuration the main stage and substage interrelate with each other in a Z direction, perpendicular to the guide plane, via the respective non-contacting plane bearings at the respective linear-motor stators. This embodiment also can include a reaction-force-attenuation mechanism situated to support a center of gravity of the linear-motor stators relative to a member vibrationally isolated from the stage apparatus. Thus, adverse effects arising from vibrations or reaction forces associated with driving of the main stage can be reduced.
In yet another embodiment, a stage apparatus according to the invention comprises (1) a support structure, (2) a stage, (3) multiple Y-axis guide members extending in a Y direction, (4) a respective Y-axis slider associated with each Y-axis guide member; (5) at least one X-axis guide member mounted to the Y-axis sliders and extending in an X direction between the Y-axis sliders, and (6) a respective X-axis slider situated and configured to slide in the X direction along the respective X-axis guide member. Each Y-axis slider is situated and configured to slide in the Y direction along the respective Y-axis guide member. The X-axis sliders are attached to the stage. At least one respective non-contacting air bearing is situated between each guide member and the respective slider, and at least one respective gas cylinder is situated and configured to drive each X-axis slider and the Y-axis sliders relative to the respective guide members. By employing at least one gas cylinder in this manner, magnetic-field fluctuations are either reduced substantially or eliminated.
Each slider desirably includes multiple respective gas bearings situated between the slider and the guide member. Each gas bearing desirably includes at least one respective guard ring situated and configured to exhaust air from the gas bearing. Also, each guard ring can be situated and configured to exhaust air from the respective gas cylinder. These configurations reduce leakage of gas from the bearings, thereby making the stage apparatus more suitable for use in a vacuum environment.
In this embodiment, each guide member desirably defines a respective internal passage that includes at least one conduit for exhausting gas from the respective gas cylinder and from the respective gas bearings. The respective internal passage also can include respective conduits for supplying air to the bearings and for recovering air from the bearings. By providing internal conduits in this manner, the need to provide external conduits to the gas cylinder or to the stage is eliminated, thereby imposing fewer restrictions on stage movement and improving stage controllability.
Yet another embodiment of a stage apparatus according to the invention is configured for moving and positioning a stage within a guide plane and relative to an axis extending perpendicularly to the guide plane. The stage apparatus comprises a guide member, a slider, a stage attached to the slider, and a drive mechanism. The slider is situated relative to the guide member and is configured to undergo a sliding motion in the guide plane relative to the guide member as guided by the guide member. The sliding motion is on at least one non-contacting gas bearing situated between the slider and the guide member. The drive mechanism is operably coupled to the slider so as to cause the sliding motion of the slider relative to the guide member. The drive mechanism comprises at least one linear motor and at least one gas cylinder. The gas cylinder is configured to provide a driving force (that assists a driving force imparted to the slider by the linear motor) during acceleration and deceleration of the slider. The gas cylinder provides a high-magnitude driving force that achieves high acceleration and deceleration characteristics. The linear motor effectively provides high-precision positioning and movement of the stage, and excellent control of stage acceleration, deceleration, and velocity during scanning exposures, for example. By using a gas cylinder, the size of the linear motor can be reduced from the size that otherwise would be required if only a linear motor were used.
The linear motor can be any of various types, such as linear motors based on electromagnetism, electrostatics, electrostriction (including ultrasonic-wave systems), or magnetostriction.
In this embodiment, the stage apparatus can include a respective guard ring associated with each gas bearing. The guard rings generally are configured to recover and exhaust air from the respective gas bearing and from the gas cylinder.
Further regarding this embodiment, a first gas cylinder and respective linear motor can be situated at a central region of the slider. Meanwhile, a second gas cylinder and respective linear motor are situated in opposition to the first gas cylinder and respective linear motor, so as to flank the slider. In this configuration the point at which driving forces meet is located substantially at the center of gravity of the cylinder. Thus, it is possible to provide the driving force at the center of gravity of the cylinder, which allows positional control to be performed with high precision at high velocity.
This embodiment can include multiple guide members desirably connected to a base by respective dampers. Such a configuration absorbs reaction forces in the X and Y directions resulting from slider movement.
Further regarding this embodiment, each linear motor can comprise a respective stator each including permanent magnets and having a C-shaped transverse profile. In such a configuration including multiple stators, the stators can be situated such that respective openings in the C-shaped profiles face away from the axis perpendicular to the guide plane.
A stage apparatus according to yet another embodiment of the invention comprises a support structure comprising multiple Y-axis guide members extending in the Y direction. A respective Y-axis slider is associated with each Y-axis guide member. Each Y-axis slider comprises at least one gas bearing and is situated relative to the respective Y-axis guide member and configured to slide on the at least one gas bearing relative to the respective Y-axis guide member, as guided by the respective Y-axis guide member, but without contacting the respective Y-axis guide member. An X-axis guide member is attached to the Y-axis sliders and extends in the X direction relative to the Y-axis guide members. The stage apparatus includes an X-axis slider comprising at least one non-contacting gas bearing. The X-axis slider is situated relative to the X-axis guide member and is configured to slide on the at least one gas bearing relative to the X-axis guide member, as guided by the X-axis guide member, but without contacting the X-axis guide member. The stage is mounted to the X-axis slider. The apparatus includes a respective drive mechanism associated with each of the Y-axis sliders and with the X-axis slider. Each drive mechanism comprises a respective linear motor and a respective gas cylinder. Each gas cylinder is connected to the respective at least one gas bearing so as to augment a driving force applied to the respective slider by the respective linear motor during acceleration and deceleration of the respective slider.
This embodiment can further comprise a respective guard ring associated with each gas bearing. The guard rings are configured to exhaust air from the respective gas bearing and from the respective gas cylinder.
With respect to each drive mechanism, the respective gas cylinder can comprise a first gas subchamber and a second gas subchamber. The first and second gas subchambers are situated in opposition to each other so as to impart motion to the respective slider in both longitudinal directions relative to the respective guide member. The first and second gas subchambers can be located in a central region of the respective slider, and desirably are separated from each other by a division plate. The first and second gas subchambers desirably are flanked by the respective linear motor. With respect to each drive mechanism, the respective linear motor can comprise a stator including permanent magnets and having a C-shaped transverse profile. The stators can be situated such that respective openings in the C-shaped profiles face away from the axis.
A stage apparatus according to yet another embodiment is used for moving and positioning a stage within a guide plane defined by first and second orthogonal dimensional axes, relative to a third axis perpendicular to the guide plane. This embodiment comprises a support structure, two first-axis sliders, a second-axis guide member, a second-axis slider, and a stage. The support structure comprises two first-axis guide members extending in the first-axis direction. Each of the first-axis sliders comprises respective non-contacting gas bearings. The first-axis sliders are situated relative to respective first-axis guide members and are configured to slide on the gas bearings relative to and as guided by the respective first-axis guide members. The second-axis guide member is attached to and extends in the second-axis direction between the two first-axis sliders. The second-axis slider comprises non-contacting gas bearings, wherein the second-axis slider is situated relative to the second-axis guide member and is configured to slide on the gas bearings relative to and as guided by the second-axis guide member. The stage is mounted to the second-axis slider. A respective gas bearing is situated on each of the upper, lower, left, and right sliding surfaces of one of the first-axis sliders. A respective gas bearing is situated on each of the upper and lower sliding surfaces of the other first-axis sliders. This configuration allows the stage apparatus to be made compact and permits ease of manufacture. Also, the number of air pads is reduced, thereby reducing the quantity of gas released from them.
Desirably, two second-axis guide members are situated parallel to each other and attached to and extending in the second-axis direction between the two first-axis sliders. This configuration reduces play of the stage around its second axis.
Further desirably, each gas bearing is an air bearing comprising a respective air pad. Each air bearing desirably comprises a respective guard ring situated and configured to recover and exhaust air discharged into the respective air bearing. This configuration reduces air leakage into a surrounding vacuum environment.
With respect to each air bearing, the respective guide member desirably includes respective conduits for supplying, recovering, and exhausting air from the air bearings on the respective slider. Each air bearing is connected to the respective conduits. This configuration eliminates the need to provide external hoses for air supply, air recovery, and exhaust.
The stage apparatus can further comprise an arm member attached to the stage. The arm member includes end portions extending from the stage in a plane parallel to the guide plane. At least one respective set of linear-motor or planar-motor movers desirably is situated on each end portion. The sets of movers are configured to interact with and move relative to respective stators of respective linear motors or planar motors, respectively, to move the stage in at least one of the first and second axis directions. These symmetrical arrangements achieve very smooth stage movement. Also, by situating the actuators at respective end portions of the arm, the actuators are distant from the stage. As a result, magnetic-field fluctuations accompanying actuator movement are prevented from reaching the stage. These motors can be based on electromagnetics, electrostatics, electrostriction, ultrasonic, or magnetostriction.
Each end portion of the arm member can comprise two respective sets of linear-motor movers. Each set of linear-motor movers is configured to interact with and move relative to a respective stator. The two respective sets of linear-motor movers associated with each end portion are disposed in a symmetrically stacked arrangement in a direction parallel to the third axis. Of the two sets of linear-motor movers on one end portion, one set drives the stage in the first-axis direction, and the other set drives the stage in the second-axis direction. Similarly, of the two sets of linear-motor movers on the other end portion, one set drives the stage in the first-axis direction, and the other set drives the stage in the second-axis direction. In this configuration, the intersection of the drive forces can be located substantially at the centroid of the moving members of the stage. As a result, drive force is applied to the centroid, allowing stage position to be controlled with high accuracy at high velocity.
The respective drive forces imparted by the linear motors associated with the end portions of the arm member desirably are centered on the centroid of the stage and the second-axis slider.
Each end portion of the arm member can have a respective set of linear-motor movers configured to move the second-axis slider, with the stage, along the second-axis guide member. In this configuration, each first-axis slider has associated therewith a respective first-axis linear motor configured to move the respective first-axis slider along the respective first-axis guide member.
The stage can be provided with a freedom to undergo an amount of xcex8-direction rotation about the third axis. In this configuration the sets of respective linear-motor movers are configured to apply a motive force to the arm member sufficient to apply a xcex8-direction rotation to the stage. This achieves an adequate amount of xcex8-direction motion without having to provide a separate mechanism for it.
Each gas bearing can be configured to provide the stage with a freedom to undergo an amount of xcex8-direction rotation about the third axis. In this configuration, the sets of respective linear-motor movers situated on the end portions of the arm member are configured to apply a motive force to the arm member sufficient to apply a xcex8-direction rotation to the stage.
In this embodiment, each linear-motor mover can be a respective armature coil exhibiting substantially no variation in magnetic field during motion of the coil relative to the respective stator. Such a configuration reduces magnetic-field fluctuations, thereby reducing adverse effects on a charged particle beam whenever the stage apparatus is used in a charged-particle-beam microlithography apparatus.
The arm member desirably defines an internal passage configured to route a coolant fluid to and from the respective sets of linear-motor movers. This configuration improves stage controllability without requiring external connecting hoses to supply coolant.
The arm member can include multiple anti-vibration actuators to reduce arm vibration. The anti-vibration actuators can be respective piezoelectric elements or magnetostrictive elements.
According to another aspect of the invention, microlithography systems are provided that comprise any of the various embodiments of stage apparatus according to the invention.
The foregoing and additional features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.